1. Field of the Invention
The present general inventive concept relates to a customer replaceable unit monitor (CRUM) unit, and a replaceable unit and an image forming apparatus comprising the CRUM unit, and a unit driving method thereof. More particularly, the present general inventive concept relates to a CRUM unit and a replaceable unit capable of computing driving conditions individually, an image forming apparatus for driving the replaceable unit based on the computed driving conditions, and a unit driving method thereof.
2. Description of the Related Art
The use of computers and computer components such as printers, scanners, copiers, or multifunction units has increased over the years.
Image forming apparatuses use ink or toner to print images on print sheets. Ink or toner is a consumable, which is exhausted at the end of a predetermined life and thus has to be replaced. Most of the time, it is not ink or toner, but a unit containing the ink or toner that is replaced. This type of unit which can be replaced during use of an image forming apparatus is called a consumable or replaceable unit.
In addition to the ink or toner unit mentioned above, the replaceable unit includes other units which are not exhausted, but may deteriorate from use or over time and thus cannot render high quality printouts at the end of their lives. For example, a laser image forming apparatus employs an electric charging unit, a transfer unit, and a fusing unit therein, and in each of the units, rollers or belts may wear out or deteriorate over time. Therefore, a good quality image cannot be produced. In order to ensure a good quality image, the replaceable units need to be replaced at appropriate intervals.
Meanwhile, the replaceable units are affected by the ambient temperature. In particular, components such as an organic photo conductor (OPC) housed inside a developing unit, or a doctor blade provided close to a developing roller, are sensitive to a temperature factor. In this case, the quality of an output image depends on changes in ambient temperature.
Accordingly, a conventional image forming apparatus employs a thermistor in the set to check the temperature changes, so that the operations of the respective replaceable units can be controlled based on the temperature changes. However, due to several limitations of the replaceable units, such as limited structure or a need to interface with the main controller in the image forming apparatus, thermistors are installed in a few limited places and cannot check the temperature accurately.
In addition, since detected temperatures can have different values depending on the places where the thermistors are installed, it is also difficult to determine the optimum driving conditions of the replaceable units accurately.
Furthermore, since the main controller is required to control an image forming process based on the temperature checks received from the thermistors, the main controller can have increased computational load, and thus can be delayed in carrying out control programs.